Stop and check valve.



G. C. DAVIS & W. A. DALEY.

STOP AND CHECK VALVE.

APPLICATION FILED NOV. 7, 190a Patented May 10, 1910.

fizvefzzfona. G207" Him/5,15 74% GEORGE G. DAVIS AND WALTER A. DALEY, GEORGE M. DAVIS REGULATOR COMPANY,

OF ILLINOIS.

OFFICE,

OF CHICAGO, ILLINOIS, ASSIGNORS TO OF CHICAGO, ILLINOIS, A CORPORATION STOP AND CHECK VALVE.

Specification of Letters Patent.

Patented May 10, TOTO.

Application filed November 7, 1908. Serial No. 461,475.

To all whom it may concern:

Be it known that we, Gnoncn C. DAVIS and IVALTER A. DALEY, citizens of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Stop and Check Valves, of which the following is a specification.

Our invention relates to stop and check valves, such as are adapted for use in connection with separate steam boilers where they are connected in batteries, and the purpose of the stop and check valve is to control the steam passage between the separate boiler and its connection with the header.

Our invention is illustrated in the accompanying drawing, wherein Figure 1 is side elevation of parts of a boiler and header connection, with a vertical section through our valve; Fig. 2 is a cross section on line 2-2 of Fig. 1.

Like parts are indicated by the same letter in all the figures.

A is the individual boiler; A the steam pipe leading thence to the valve; A the pipe leading from the valve to the steam header A into which all the boilers are connected, and from which the steam supply is taken.

B is a pilot valve; B the pipe leading thence to the boiler A; B the pipe leading thence to our valve, and B the pipe lead ing from the pilot valve to the steam header.

C is the body of our stop valve, having the end 0 to which the pipe A is attached, and the end C to which the pipe A is attached. It also has the diaphragm G in which is placed the seat bushing C to receive the valve C on the stem C.

C is the cover of the valve secured in position by the bolts C From this cover rise the two side members of the yoke, D D. They are connected above by the cross yoke piece or head D Laterally projecting from the side members of this yoke are the lugs D D in which is journaled the shaft E. The shaft carries at its outer end, the arm E on which is adjustably mounted the weight E In the middle of the shaft is secured the sleeve E having the arms E E from each of which projects inwardly a finger E These fingers are received into the annular groove E in a projection F attached to the bottom of the cup F and screw-threaded at F to the stem C". This cup is filled with oil F to serve as a dash pot. In this-form of the device the cup itself is movable, and its piston F is fixed as indicated. The piston may assume any desired shape, but is preferably provided with pockets F perforated at their lower ends at F, so as to open into the cup F or oil chamber F The pipe 13 opens into one or more of these air chambers F as indicated at F The piston is held in position by the screw rods G G which take into its upper portion, and are held adjustably in position by the nuts G G On the top of these rods is placed the bar G held in position by the nutsG G and bearing upon the stuffing boX cap G to close the stuffing box chamber G through which moves the shaft G. This shaft has the hand wheel G screw threaded at G into the piston, and has the projecting end G adapted when the hand wheel is operated to impinge upon the bottom of the cup, and thus enable the direct application of power to the cup to close the valve.

The pilot valve B consists of the casing and the balanced valve 13 on the stem 13 attached to the diaphragm B in the chamber B into which the pipe B opens. The arrangement is such as to keep the valve shut between the boiler A and the chamber F when the pressures in the boiler and header are the same, and to open up the connection between the pipes B and B when the pressure in the header A becomes less than the pressure in the boiler A. Any structure which will accomplish this result we call a pilot valve.

It is obvious that various changes can be made in the form and construction of our device without departing from the spirit of our invention. If protection is to be had only against breakages in the boiler, then the pilot valve and its associated parts are unnecessary. In that case also the piston fitted into the oil cup could be movable.

hen the steam pipe B is to be connected with the chamber in such piston, then the piston mustbe fixed as shown in our draw- 111 I is a screw whereby the eifective size of the opening F may be varied. The size and weight of the dash-pot portions and associated parts is of course a variable quantity and may be greater or less in proportion to the cross sectional area of the rod C. The weighted arm E is adjustably secured as indicated by a set screw to the shaft E so that it can be extended in either direction.

The use and operation of our invention are as tollows:Assuming the parts to be in the positions indicated, and all properly connected, if the steam is generated in the boiler A, it tends to flow through pipe A and through the valve into the header A lifting the valve C for thatpurpose. The changes in the situation may cause the valve to fluctuate but the dash pot efiect prevents hammering or abrupt movement of the valve. It now the boiler breaks or leaks or its steam supply becomes inadequate, there is a tendency for the steam in the header, generated by the other boilers in the battery, to rush out into the damaged boiler. To do this however it must pass the valve C. This valve the flow of steam will easily close, provided it is suitably balanced, but obviously there is a steam pressure upwardly on the bottom of the valve for a space equal in cross section to the cross section of the stem C which is not balanced, but which is exposed at the other end only to the air pressure. The current of the steam therefore tends on the one hand to close the valve and on the other to supply a pressure below the valve to keep it open. The cup on the dash pot structure attached to the top of the valve is balanced by the weight E This weight is adjustable along the arm and is to be set at a point in proper relation to the normal pressure in the header A and its adjustment will also depend upon the area of the cross section of the stem C. When properly adjusted the valve is balanced so that the tendency of the steam to keep the valve open is overcome. The flow of the steam therefore from the header A to the defective boiler A. closes the valve C and maintains this condition until steam of a predetermined pressure is again generated in the boiler A. On the other hand, if a defect arises in the header A or some boiler connected with it, or if some boiler or pipe bursts, the pressure in the header A will be reduced, whereupon the diaphragm B being freed from the pressure on its upper side is moved upwardly and the balance valve is operated to open the connection between pipes B and B and allow the steam pressure in the boiler A to be transferred through pipe B to the annular chamber F in the piston. This pressure applied to the top of the oil in that chamber, forces the cup or body of the valve with the stem C downwardly to seat the valve (J on its valve seat and stop the flow from pipe A through the valve into the header A It will be observed that in connection with our check valve we employ an exterior dashpot and in connection with the movable part of the dash pot we employ a balancing apparatus to compensate for the steam pressure on the cross sectional area of the stem. Our balancing device is adjustable to accommodate this balance to various predetermined pressure limits in the header. It will also be observed that the piston is normally stationaryand the cup movable and that in the form of our device here shown the hand wheel stein passes through the stationary piston so as to impinge upon the movable part of the dash pot and positively seat the valve when desired. These parts are all supported on the yoke which rises from the top of the check valve.

The boiler A we call the first source of steam supply, and the heade A the second source of steam supply. There are two steam connections between them; one, within which the check valve is located, the other within which the pilot valve is located. As previously explained this pilot valve operates to turn the pressure of the first source of steam supply into the dash-pot chamber when there is an abnormal reduction of the pressure in the header. Since the area of the movable part of the dash-pot is greater than the effective area of the valve C this action will positively seat the valve C. On the other hand, if there is an abnormal reduction of pressure in the boiler A of the first source of supply, the pressure on the boiler side of the valve C will be a trifle less than on the other side, but not suflieient to close the valve because though the pressure is lower it has the advantage of working outardly against an area equal to the cross sectional area of the stem C against air pressure. It is to compensate for this inequality or balance it that we employ our balancing device or rock shaft and weighted arm.

As heretofore described, the weight is adapted to balance the pressure incident to the cross sectional area of the red C, but it, as previously explained, the dash-pot portions were made sutliciently heavy they would balance the pressure due to the cross sectional area of the rod C or there might be other arrangements so as to get rid of the eiiect of the cross sectional area of that rod either temporarily or for certain conditions of variation of the pressure in the header. The weight, therefore, by shifting its position on the arm and by shifting the position of the arm on the rod may be made to balance or compensate for any such inequality at any given pressure in the header. It may balance the pressure due to the cross sectional area of the rod C or it may balance the inequality in weight between the dash-pot portions and the valve. In short, the weight device is a balancing device to compensate either for the steam pressure on the cross sectional area of the dash-pot stem or the inequality in the weights of the moving portions or either.

I claim:

1. In a stop and check valve for controlling a steam passage, the combination of a valve with an exterior dash-pot removed from the influence of the steam associated therewith to regulate its action.

2. In a stop and check valve for controlling a steam passage, the combination of a valve with an exterior dash-pot removed from the influence of the steam associated therewith to regulate its action, and a balancing device to compensate for the steam pressure on the cross sectional area of such dash-pot stem.

3. In a stop and check valve for controlling a steam passage, the combination of a valve with an exterior dash-pot removed from the influence of the steam associated therewith to regulate its action, and a balancing device to compensate for the steam pressure on the cross sectional area of such dash-pot stem, said balancing device adjustable to accommodate for predetermined pressures in the steam header.

l. In a stop and check valve for controlling a steam passage, the combination of a valve with an exterior dash-pot removed from the influence of the steam associated therewith to regulate its action, and a balancing device to compensate for the steam pressure on the cross sectional area of such dash-pot stem, such balancing device consisting of a rock shaft associated with the movable part of the dash-pot and a weighted arm projecting therefrom.

5. In a stop and check valve for controlling a steam passage, the combination of a valve with an exterior dash-pot removed from the influence of the steam associated therewith to regulate its action, and a balancing device to compensate for the steam pressure on the cross sectional area of such dash-pot stem, said balancing device adjustable to accommodate for predetermined pressures in the steam header, such balancing device consisting of a rock shaft associated with the movable part of the dash-pot and a weighted arm projecting therefrom.

6. In a stop and check valve for controlling a steam passage, the combination of a valve with a dash-pot whose movable part is connected with the valve, a balancing device connected with such movable part and adapted to compensate for the pressure on the cross sectional area of the dash-pot stem.

7. In a stop and check valve for controlling a steam passage, the combination of a valve with a dash-pot whose movable part is connected with the valve, a balancing device connected with such movable part and adapted to compensate for the pressure on the cross sectional area of the stem, and a threeway pilot valve with connections on both sides of the main valve and another to the dash-pot.

8. A stop and check valve comprising a valve, a stem, a dash-pot having a movable inclosing cylinder attached to said stem, a rock shaft, connections thence to the movable portion of the stem, and a weighted arm on the rock shaft.

9. A stop and check valve comprising a valve, a stem, a dash-pot having a movable inclosing cylinder attached to said stem, a rock shaft, connections thence to the movable portion of the stem, a weighted arm on the rock shaft, and a normally fixed piston for such dash-pot.

10. A stop and check valve comprising a valve, a stem, adash-pot having a movable portion attached to said stem, a rock shaft, connections thence to the movable portion of the stem, a weighted arm on the rock shaft, a fixed piston for such dash-pot, and a hand wheel and stem which passes through the piston and abuts the movable portion of the dash-pot.

11. A device for controlling the steam connection between two sources of supply comprising a connecting pipe between the two sources, a stop and check valve in such pipe, a stem leading from the valve, a dashpot to regulate the action of the stem, a second steam connection between the two sources, a pilot valve, and a connection thence to the clash pot.

12. A device for controlling the steam connection between two sources of supply comprising a connecting pipe between the two sources, a stop and check valve in such pipe, a stem leading from the valve, a dashpot to regulate the action of the stem, a second steam connection between the two sources, a pilot valve, and a connection thence to the dash-pot, said pilot valve adapted to connect the chamber of the dash pot with the first source of supply when the pressure in the second source of supply is abnormally reduced.

13. A device for controlling the steam connection between two sources of supply comprising a connecting pipe between the two sources, a stop and check valve in such pipe, a stem leading from the valve, a dashpot to regulate the action of the stem, a second steam connection between the two sources, a pilot valve, and a connection thence to the dash-pot, said dash pot having movable part connected to the stem of the valve, and a balancing device associated therewith to compensate for the pressure on the cross sectional area of the valve stem.

14. A device for controlling the steam connection between two sources of supply comprising a connecting pipe between the two sources, a stop and check valve in such pipe, a stem leading from the valve, a dash-pot to regulate the action of the stem, a second steam connection between the two sources, a pilot valve, a connection thence to the daslr pot, said dash-pot having a movable part connected to the stem of the valve, and a balancing device associated therewith to compensate for the pressure on the cross sectional area of the valve stem, said balancing device adjustable to adapt it to varying pressures on the source of steam supply.

15. In a stop and check valve for controlling a steam passage, the combination of a valve with an exterior dash-pot associated therewith to regulate its action, and a balancing device to compensate for the in equalities between the valve and the movable portion of the dash-pot.

16. In a stop and check valve for controlling a steam passage, the combination of a valve with an exterior two-chamber dashpot removed from the influence of the steam associated therewith to regulate its action, and means for regulating the flow of fluid from one chamber to the other.

17. In a stop and check valve for controlling a steam passage, the combination of a valve disk with an exterior dash-pot removed from the influence of the steam associated therewith to regulate its action, a stem connecting said dash-pot and disk, and means for balancing the steam pressure on the cross sectional area of the stem.

18. In a stop and check valve for controlling a steam passage, the combination of a valve disk with an exterior dash-pot removed trom the influence of the steam associated therewith to regulate its action, and means to compensate for the weight of the moving part less the pressure 011 the cross sectional area of such dash pot stem.

19. In a stop and check valve for controlling a steam passage, the combination of a valve with an exterior dash-pot removed from the influence of the steam associated therewith to regulate its action, a connection between the valve and the moving portion of the dash-pot, and a balancing device associated with such movable part of the dash-pot.

20. In a stop and check valve for control- 1 ling a steam passage, the combination of a valve with an exterior dash-pot removed from the influence of the steam associated therewith to regulate its action, a connection between the valve and the moving portion of the dash-pot, and a balancing device associated with such movable part of the dashpot consisting of an adjustable weight.

21. I11 a stop and check valve for controlling a steam passage, the combination of a valve with an exterior dash-pot removed from the influence of the steam associated therewith to regulate its action, a connection between the valve and the moving portion of the dash-pot, and a balancing device asso ciated with such movable part of the dashpot consisting of a weight adjustable to vary its effective power and the direction of its pull.

22. A stop and check valve comprising a valve, a stem, a dash-pot having a movable portion attached to said stem, a rock shaft, connections thence to the movable portion of the stem, a weighted arm on the rock shaft and a normally fixed piston and a movable cylinder for such dash-pot.

23. A stop and check valve comprising a valve, a stem, a dash-pot having a movable inclosing cylinder attached to said stem, a rock shaft, connections thence to the movable portion of the stem, a weighted arm on the rock shaft, and means for adjusting the resistance to the movement in the dash-pot.

2A. A stop and check valve comprising a valve, a stem, a dash-pot having a movable portion attached to said stem, a rock shaft, connections thence to the movable portion of the stem, a weighted arm on the rock shaft, and means for adjusting the resistance to the movement in the dash-pot, said means containing a normally fixed piston, a movable cylinder, a chamber in said piston, an opening from the dash pot chamber into said chamber, and means for regulating the size of said opening.

GEORGE C. DAVIS. WVALTER A. DALEY.

Witnesses EDNA K. REYNOLDS, LUcr A. FALKENBERG. 

